1. Field of the Invention
The present invention relates to a synthetic process for producing a ketazine, and more specifically, it relates to an industrial preparation process for producing a ketazine and a synthetic process for producing a hydrazine hydrate from the obtained ketazine. Incidentally, this ketazine is useful as an intermediate material from which the hydrazine hydrate is usually prepared.
2. Description of the Related Arts
Heretofore, as a preparation process of a hydrazine hydrate, there has been a process which comprises oxidizing ammonia with an oxidizing agent such as sodium hypochlorite or hydrogen peroxide in the presence of a ketone to synthesize a ketazine, and then hydrolyzing this ketazine.
In "Kirk-Othmer", 3rd Edition, Vol. 12, p. 734-755, there has been described a process for preparing a ketazine from hydrogen peroxide, ammonia and a ketone in the presence of an aqueous solution containing acetamide and sodium phosphate as shown by the chemical equation EQU 2NH.sub.3 +2R.sub.1 R.sub.2 C=O+H.sub.2 O.sub.2 .fwdarw.R.sub.1 R.sub.2 C=N-N.dbd.CR.sub.1 R.sub.2 +4H.sub.2 O.
In this process, the unreacted ketone present in the reaction mixture containing the ketazine can be collected therefrom and then reused. In this case, however, impurities produced during the synthetic reaction of the ketazine are collected together with the ketone, and the ketone containing the impurities is then reused by circulation, so that the impurities are accumulated in the circulated ketone, with the result that a reaction yield deteriorates.